JP2691456B2 - Manufacturing method of composite type damping steel sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention does not need to increase the surface pressure applied when diffusion-bonding an insert metal sandwiched between steel sheets to both steel sheets by annealing. The present invention relates to a method for manufacturing a composite type vibration damping steel plate.

[Conventional technology]

In recent years, due to the problem of noise pollution and the demand for a quiet environment, interest in vibration damping materials has increased, and its application range is expanding.

In such a situation, as a composite type vibration damping steel plate that has excellent heat resistance and weldability, can be heat treated, and can be applied to high-strength members, it is almost uniform between the superposed steel plates. A metallurgical bond formed mainly by a metallurgical bond due to diffusion between the insert metal having a minute width and distributed between the two steel plates and the metallurgical part except the metallurgical bond. Abuts without joining to
A composite vibration-damping steel sheet in which the ratio of the total of the cut surfaces of the joints on the same plane as the contact surface to the area of the steel sheet (hereinafter sometimes referred to as the proportion of the total cross-sectional area of the joint) is 0.5 to 50% Have been proposed by the present applicant and confirmed to have excellent vibration damping performance (Japanese Patent Laid-Open No. 63-246235).
No.). As a method for manufacturing this composite type vibration-damping steel sheet, insert metal with a small width is sandwiched between the steel sheets in a substantially uniform distribution state, and a surface pressure is applied between the steel sheets under an inert gas atmosphere. In the above, a method for manufacturing a composite vibration-damping steel sheet in which annealing is performed at a temperature at which diffusion occurs between each steel sheet and the insert metal has been proposed together with the above, and it has been confirmed that the steel sheet has sufficient bonding strength (JP 63-24
See 6238).

In the method of manufacturing the composite vibration-damping steel plate, as the type of insert metal, it is considered that nonferrous metal such as Cu, Ni, Ag or the like that can be joined to the steel plate by diffusion without generating brittle alloy etc. is good. However, it is not particularly limited, and in reality, steel is the most easy-to-use metal in terms of cost and scraping. As the type of the steel, a mild steel which is inexpensive and can be easily processed into a thin shape which is the shape of insert metal, such as low carbon aluminum killed steel or titanium killed steel, has been used.

However, when using mild steel such as the above-mentioned low carbon aluminum killed steel and titanium killed steel as the insert metal, a large surface pressure is required to obtain sufficient bonding strength, so that there is a surface that is difficult to manufacture as follows. . That is, as in the manufacturing method described above, annealing is performed while applying surface pressure to the steel sheet surface to cause diffusion between the insert metal and the steel sheet to join, but production is performed on an industrial scale. In some cases, it may be necessary to increase the size of the manufacturing equipment including a pressurizing device to apply a large surface pressure, or if the equipment remains small, the bonding strength may become insufficient, and it may take a long time. However, there are drawbacks such as requiring annealing.

[Problems to be solved by the invention]

The present invention eliminates the above-mentioned drawbacks of the prior art, and when an insert metal sandwiched between steel plates is diffuse-bonded to both steel plates by annealing to produce a composite vibration-damping steel plate, a surface pressure applied during annealing. The problem is to make it not necessary to make it too large.

[Means for solving the problem]

The present invention will be described together with the process of investigations conducted by the present inventors to solve the above problems.

First, the behavior of the insert metal and the steel sheet in the step of annealing while pressurizing was investigated in detail. As a result, the following findings were obtained.

When annealed while applying pressure, first, at the interface between the insert metal and the steel sheet, plastic deformation occurs in both of them, the unevenness of the surface is crushed, the gaps existing at the interface are reduced, and the degree of adhesion increases. As the annealing further progresses, both metal atoms diffuse to the other side, and the small gap as described above gradually fills, and finally the gap disappears and the insert metal and the steel plate are completely joined. The surface irregularities referred to here include not only those caused by macroscopic deformation of insert metal and steel plates, but also microscopic irregularities at the same level as the surface roughness. Is also present.

From such knowledge, in order to make the joining of the insert metal and the steel plate stronger and more reliable, first, for example, annealing for an extremely long time may be considered so that sufficient diffusion occurs. Because it causes a decrease in productivity,
Rather, it is considered important to promote plastic deformation of surface irregularities and increase the degree of adhesion. Thus, one of the methods for promoting the deformation of the unevenness is to increase the surface pressure, but this leads to an increase in the size of the manufacturing equipment as described above, which does not solve the problem. .

Therefore, in order to solve the above-mentioned problems, it is important to select a material such as a steel plate and / or an insert metal that is likely to be plastically deformed so that the unevenness is easily crushed. However, the type of steel plate is determined by the application of the composite type vibration damping steel plate, etc., and it is practically difficult to select it from the above viewpoint alone. Therefore, it has been considered that selecting an appropriate material for the remaining insert metal, that is, one having a small deformation stress during hot working is an extremely effective means for solving the above problems.

The present invention has been made through further studies based on the above-described considerations and investigating the composition of the insert metal so as to obtain an appropriate material.

Also in the present invention, the insert metal having a minute width is sandwiched between the steel plates in a substantially uniform distribution state so that the ratio of the cross-sectional area of the entire joint is a predetermined ratio, and the surface pressure is applied between the steel plates. In this state, annealing is performed in an inert atmosphere at a temperature at which diffusion occurs between each steel sheet and the insert metal, as in the conventional method for manufacturing a composite vibration-damping steel sheet.

The feature of the present invention is that, as an insert metal, in weight%, C ≦ 0.010%, Si ≦ 0.01%, Mn ≦ 0.15%, P ≦ 0.01%, S ≦ 0.0.
1%, N ≦ 0.010% and C + N ≦ 0.012%,
The balance is the use of steel insert metal consisting of Fe and unavoidable impurities.

The reasons for limiting the composition shown above as steel used as insert metal will be described below.

C is an interstitial solid solution element, and is one of the elements that most affects the increase in deformation stress at high temperatures. Therefore, it is effective to reduce the content of C as much as possible, and in order to sufficiently reduce the deformation stress at high temperature, it is necessary to set it to 0.010% or less.

N is one kind of impurities mixed in from the atmosphere when steel is melted, but, like C, it is an element that increases the deformation stress with a small amount of content. Therefore, it is effective to reduce the content of N as much as possible, and in order to sufficiently reduce the deformation stress at high temperature, it is necessary to set it to 0.010% or less.

Here, since C and N are elements having the same influence, if the content of either one is lowered,
It is not possible to sufficiently reduce the deformation stress. Therefore, C
The content of + N must be 0.012% or less.

P and S are impurities usually contained in steel, and these elements also increase the deformation stress. Therefore, it is desirable to reduce the content as much as possible, and it is necessary to make the content 0.01% or less.

Since Si is an element that not only increases the deformation stress but also easily oxidizes, it forms an oxide at the interface between the insert metal and the steel sheet during annealing, which impedes element diffusion and reduces the bondability. . Therefore, it is desirable to reduce the content as much as possible, and it is necessary to set it to 0.01% or less.

Mn is also an element that increases the deformation stress, but its effect is smaller than Si, so it is not necessary to restrict it to a lower content than Si, but 0.15% is required to reduce the deformation stress and improve the bondability. Must be:

In addition, although it is desirable to reduce the content of elements contained in steel as much as possible, it is not particularly limited as long as it is contained in ordinary steelmaking.

〔Example〕

Hereinafter, the method for manufacturing the composite vibration-damping steel sheet according to the present invention will be described more specifically with reference to Examples and Comparative Examples.

In a high-frequency melting furnace, five types of steel with the chemical composition shown in Table 1 were melted into 30 kg ingots, respectively, and then hot forged, hot rolled, and cold rolled through the steps of 0.2 mm in thickness. Five types of thin plates were manufactured. Each thin plate was cut into 2.0 mm square chip-shaped thin pieces, which were used as insert metals. Among the No. steels shown in Table 1, III is the content of (C + N), IV is the content of C, Si, Mn and (C + N), V is the content of Ti, Each is outside the composition of the insert metal specified in the method of the present invention.

On the other hand, two types of steel, low carbon steel and carbon tool steel having the chemical compositions shown in Table 2 were melted in a converter and made into slabs by continuous casting, and then hot rolling, cold rolling, Two types of steel plates having a plate thickness of 1.0 mm, a width of 600 mm and a length of 1000 mm were manufactured through the respective shearing steps.

After degreasing and cleaning the surface of the above steel sheet, insert metal of No. I steel mentioned above on this steel sheet at about 20 per 1 m ^2.
A set of unbonded composite vibration-damping steel plate laminates (hereinafter referred to as unbonded laminates) by stacking the above-mentioned types of steel plates that have been degreased and washed on top of this Got In this way, using each insert metal, 5 sets for each type of low carbon steel plate and carbon tool steel plate, a total of 10 sets of unbonded laminates were stacked, and 3500 kg was placed on the top set of steel plates in the annealing furnace.
Was annealed while applying a surface pressure (5833 kg per 1 m ² ) with the weight of No. ³ placed. This annealing is about 150 ℃ / hour, 900 ℃
× 5 hours of soaking and heating at a heating history of about 50 ° C / hour (In such a case, conventionally, a weight of 8750 kg per 1 m ² was used or heating time was 10 hours. ). The annealing atmosphere was 5% H ₂ + 95% N ₂ . Diffusion bonding between the insert metal and each steel sheet was performed by annealing while applying surface pressure under the above conditions.

Regarding the composite vibration-damping steel plate obtained in the above process (hereinafter sometimes simply referred to as composite steel plate), a T-shape with a width of 25 mm shown in Fig. 1 (a) and (b) to evaluate the degree of joining The bonding strength was measured by a tensile test method using a mold test piece. Table 3 shows the results. When measuring the joining strength, the joining strength per insert metal was measured.

As is clear from this result, in comparison with the conventional low carbon aluminum killed steel or the one using low carbon titanium killed steel as the insert metal, in the example using the insert metal of the present invention method, the joining strength is obviously higher. I understand.

Regarding the vibration damping properties of the composite steel plates obtained in these Examples and Comparative Examples, the vibration damping property measurement object 2 was suspended and held by the thread 3 on the column frame 1 of the device shown in FIG. Table 3 also shows the sound pressure level measured by the microphone 6 by receiving the impact sound of the rotatable hammer 4 by rotating and dropping it from the horizontal state, and comparing it with the example for each material of the steel plate. Comparing the example with the sound pressure level, there is almost no difference between the two. The sound pressure level of the composite vibration-damping steel plate obtained by the method of the present invention is significantly lower than that of the single steel plate shown as Reference Examples 1 and 2, and has sufficient performance as the vibration-damping steel plate. Was confirmed.

〔The invention's effect〕

As described above in detail, according to the method for manufacturing the composite type vibration-damping steel sheet according to the present invention, by using the steel having the specific composition as the insert metal, the insert metal is sandwiched between the steel sheets and annealed for diffusion bonding. At times, it is not necessary to apply a large surface pressure or anneal for an extremely long time, and strong and reliable joining can be performed. The present invention as described above is extremely useful for producing a composite vibration-damping steel sheet on an industrial scale.

[Brief description of the drawings]

FIG. 1 is a diagram showing the shape of a test piece for measuring the bonding strength of a composite steel sheet, (a) is a front view, (b) is a side view, and FIG. 2 is a sound pressure level of tapping sound. It is a perspective view of the apparatus which does. In the drawing 1 ... Support post 2 ... Vibration damping measurement object 3 ... Thread 4 ... Hammer 5 ... Microphone 6 ... Amplifier

Claims (1)

(57) [Claims] 1. An insert metal having a small width is sandwiched between steel sheets in a substantially uniform distribution state, and each steel sheet and the insert metal are placed under an inert gas atmosphere in a state where a surface pressure is applied between the steel sheets. When manufacturing a composite vibration-damping steel sheet by annealing at a temperature at which diffusion occurs between C, 0.0%, C ≦ 0.010%, Si ≦ 0.01%, Mn ≦ 0.15% and P ≦ as insert metal.
0.01%, S ≦ 0.01%, N ≦ 0.010% and C + N ≦ 0.0
A method for producing a composite vibration-damping steel sheet, characterized by using an insert metal of steel containing 12% and the balance being Fe and inevitable impurities.